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Sędek Ł, Flores-Montero J, van der Sluijs A, Kulis J, te Marvelde J, Philippé J, Böttcher S, Bitter M, Caetano J, van der Velden VHJ, Sonneveld E, Buracchi C, Santos AH, Lima M, Szczepański T, van Dongen JJM, Orfao A. Impact of Pre-Analytical and Analytical Variables Associated with Sample Preparation on Flow Cytometric Stainings Obtained with EuroFlow Panels. Cancers (Basel) 2022; 14:cancers14030473. [PMID: 35158741 PMCID: PMC8833630 DOI: 10.3390/cancers14030473] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/11/2022] [Accepted: 01/13/2022] [Indexed: 02/04/2023] Open
Abstract
Simple Summary Objective interpretation of flow cytometry may be hampered by a lack of standardized sample preparation procedures. The EuroFlow consortium conducted a series of experiments to determine the potential impact of different pre-analytical and analytical factors on the variability of results in terms of relative cell populations distribution and marker expression levels. The experiments were performed on healthy donors and patients with different hematological malignancies (e.g., acute leukemia, lymphoma, multiple myeloma, and myelodysplastic syndrome) to mimic real-world clinical settings. Overall, the results showed that sample storage conditions, anticoagulant use, and sample processing protocol might need to be tailored for sample and cell type(s), as well as to the specific markers evaluated. However, defining of well-balanced boundaries for storage time to 24 h, staining-acquisition delay to 3 h, and choosing a washing buffer of pH within the range of 7.2 to 7.8 would be a valid recommendation for most applications and circumstances described herein. Abstract Objective interpretation of FC results may still be hampered by limited technical standardization. The EuroFlow consortium conducted a series of experiments to determine the impact of different variables on the relative distribution and the median fluorescence intensity (MFI) of markers stained on different cell populations, from both healthy donors and patients’ samples with distinct hematological malignancies. The use of different anticoagulants; the time interval between sample collection, preparation, and acquisition; pH of washing buffers; and the use of cell surface membrane-only (SM) vs. cell surface plus intracytoplasmic (SM+CY) staining protocols, were evaluated. Our results showed that only monocytes were represented at higher percentages in EDTA- vs. heparin-anticoagulated samples. Application of SM or SM+CY protocols resulted in slight differences in the percentage of neutrophils and debris determined only with particular antibody combinations. In turn, storage of samples for 24 h at RT was associated with greater percentage of debris and cell doublets when the plasma cell disorder panel was used. Furthermore, 24 h storage of stained cells at RT was selectively detrimental for MFI levels of CD19 and CD45 on mature B- and T-cells (but not on leukemic blasts, clonal B- and plasma cells, neutrophils, and NK cells). The obtained results showed that the variables evaluated might need to be tailored for sample and cell type(s) as well as to the specific markers compared; however, defining of well-balanced boundaries for storage time, staining-to-acquisition delay, and pH of washing buffer would be a valid recommendation for most applications and circumstances described herein.
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Affiliation(s)
- Łukasz Sędek
- Department of Microbiology and Immunology, Medical University of Silesia in Katowice (SUM), 41-808 Zabrze, Poland;
| | - Juan Flores-Montero
- Cancer Research Center (IBMCC, USAL-CSIC), Department of Medicine and Cytometry Service (NUCLEUS), University of Salamanca (USAL), 37007 Salamanca, Spain; (J.F.-M.); (J.J.M.v.D.)
- Institute of Biomedical Research of Salamanca (IBSAL), 37007 Salamanca, Spain
- Center of Biomedical Network Research in Cancer (CIBER ONC), Carlos III Institute of Health, 28029 Madrid, Spain
| | - Alita van der Sluijs
- Department of Immunology, Leiden University Medical Center (LUMC), 2300 RC Leiden, The Netherlands;
| | - Jan Kulis
- Department of Pediatric Hematology and Oncology, Medical University of Silesia in Katowice (SUM), 41-800 Zabrze, Poland; (J.K.); (T.S.)
| | - Jeroen te Marvelde
- Department of Immunology, Erasmus MC, University Medical Center Rotterdam, 3015 CN Rotterdam, The Netherlands; (J.t.M.); (V.H.J.v.d.V.)
| | - Jan Philippé
- Department of Diagnostic Sciences, Ghent University, 9000 Ghent, Belgium;
| | - Sebastian Böttcher
- Special Hematology Laboratory, Medical Clinic III, Hematology, Oncology and Palliative Medicine, Rostock University Medical Center, 18057 Rostock, Germany;
| | - Marieke Bitter
- European Scientific Foundation for Laboratory Hemato Oncology (ESLHO), 2333 ZA Leiden, The Netherlands;
| | - Joana Caetano
- Clinical Flow, Hemato-Oncology Unit, Champalimaud Foundation, 1400-038 Lisboa, Portugal;
| | - Vincent H. J. van der Velden
- Department of Immunology, Erasmus MC, University Medical Center Rotterdam, 3015 CN Rotterdam, The Netherlands; (J.t.M.); (V.H.J.v.d.V.)
| | - Edwin Sonneveld
- Princess Maxima Center for Pediatric Oncology, 3584 CS Utrecht, The Netherlands;
| | - Chiara Buracchi
- Pediatric Clinic of Milano-Bicocca, Tettamanti Research Center, Monza (TRC), 20900 Monza, Italy;
| | - Ana Helena Santos
- Department of Hematology, Central Hospital of Porto (CHP), 4099-001 Porto, Portugal; (A.H.S.); (M.L.)
| | - Margarida Lima
- Department of Hematology, Central Hospital of Porto (CHP), 4099-001 Porto, Portugal; (A.H.S.); (M.L.)
| | - Tomasz Szczepański
- Department of Pediatric Hematology and Oncology, Medical University of Silesia in Katowice (SUM), 41-800 Zabrze, Poland; (J.K.); (T.S.)
| | - Jacques J. M. van Dongen
- Cancer Research Center (IBMCC, USAL-CSIC), Department of Medicine and Cytometry Service (NUCLEUS), University of Salamanca (USAL), 37007 Salamanca, Spain; (J.F.-M.); (J.J.M.v.D.)
- Department of Immunology, Leiden University Medical Center (LUMC), 2300 RC Leiden, The Netherlands;
| | - Alberto Orfao
- Cancer Research Center (IBMCC, USAL-CSIC), Department of Medicine and Cytometry Service (NUCLEUS), University of Salamanca (USAL), 37007 Salamanca, Spain; (J.F.-M.); (J.J.M.v.D.)
- Institute of Biomedical Research of Salamanca (IBSAL), 37007 Salamanca, Spain
- Center of Biomedical Network Research in Cancer (CIBER ONC), Carlos III Institute of Health, 28029 Madrid, Spain
- Correspondence: ; Tel.: +34-923-294-811
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The influence of fixation of biological samples on cell count and marker expression stability in flow cytometric analyses. Cent Eur J Immunol 2021; 45:206-213. [PMID: 33456333 PMCID: PMC7792444 DOI: 10.5114/ceji.2020.95858] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 10/11/2019] [Indexed: 11/24/2022] Open
Abstract
The most common applications of flow cytometry (FC) include diagnostics of haemato-oncological disorders, based on analysis of bone marrow, peripheral blood (PB), or cerebrospinal fluid (CSF) samples. A proper diagnostic process requires standardisation in setting the optimal time frame between material collection and the assay. Unfortunately, this might be difficult to achieve in daily practice due to unintended shipment delays, which might compromise large-scale multicentre studies. Thus, material fixation should be considered as a solution. The most widely used fixative agents are: paraformaldehyde, TransFix®, Cyto-Chex®, and serum-containing media. In this review, we attempted to summarise the literature data on the influence of sample storage under different temperatures and times combined with different fixation conditions on the cell count and marker expression levels. Based on the findings of several extensive studies employing fixed PB samples, it can be concluded that the performance of particular fixative greatly depends on the analysed marker and specific PB cell population expressing a given antigen. Preservation of absolute cell count was usually better in Cyto-Chex®-fixed PB samples, whereas TransFix® tended to better stabilise marker expression levels. CSF-based studies reveal that both serum-containing media and TransFix® can prevent cellular loss and enhance FC-based detection of leptomeningeal localisations of haematological malignancies, the latter being more available and having longer shelf-life. As both cell count and marker expression level are the main determinants of quality of biological samples dedicated to FC analyses, it remains to be addressed by the investigators which is the fixative of choice for their specific research aims.
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Trahtemberg U, Grau A, Tabib A, Atallah M, Krispin A, Mevorach D. Identification and Characterization of Two Human Monocyte-Derived Dendritic Cell Subpopulations with Different Functions in Dying Cell Clearance and Different Patterns of Cell Death. PLoS One 2016; 11:e0162984. [PMID: 27690130 PMCID: PMC5045195 DOI: 10.1371/journal.pone.0162984] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 08/31/2016] [Indexed: 12/23/2022] Open
Abstract
Human monocyte-derived dendritic cells (mdDCs) are versatile cells that are used widely for research and experimental therapies. Although different culture conditions can affect their characteristics, there are no known subpopulations. Since monocytes differentiate into dendritic cells (DCs) in a variety of tissues and contexts, we asked whether they can give rise to different subpopulations. In this work we set out to characterize two human mdDC subpopulations that we identified and termed small (DC-S) and large (DC-L). Morphologically, DC-L are larger, more granular and have a more complex cell membrane. Phenotypically, DC-L show higher expression of a wide panel of surface molecules and stronger responses to maturation stimuli. Transcriptomic analysis confirmed their separate identities and findings were consistent with the phenotypes observed. Although they show similar apoptotic cell uptake, DC-L have different capabilities for phagocytosis, demonstrate better antigen processing, and have significantly better necrotic cell uptake. These subpopulations also have different patterns of cell death, with DC-L presenting an inflammatory, "dangerous" phenotype while DC-S mostly downregulate their surface markers upon cell death. Apoptotic cells induce an immune-suppressed phenotype, which becomes more pronounced among DC-L, especially after the addition of lipopolysaccharide. We propose that these two subpopulations correspond to inflammatory (DC-L) and steady-state (DC-S) DC classes that have been previously described in mice and humans.
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Affiliation(s)
- Uriel Trahtemberg
- The Laboratory for Cellular and Molecular Immunology, Department of Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Amir Grau
- The Laboratory for Cellular and Molecular Immunology, Department of Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Adi Tabib
- The Laboratory for Cellular and Molecular Immunology, Department of Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Mizhir Atallah
- The Laboratory for Cellular and Molecular Immunology, Department of Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Alon Krispin
- The Laboratory for Cellular and Molecular Immunology, Department of Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Dror Mevorach
- The Laboratory for Cellular and Molecular Immunology, Department of Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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Holme AL, Yadav SK, Pervaiz S. Automated laser scanning cytometry: a powerful tool for multi-parameter analysis of drug-induced apoptosis. Cytometry A 2007; 71:80-6. [PMID: 17200953 DOI: 10.1002/cyto.a.20362] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Simultaneous analysis of multiple intracellular events is critical for assessing the effect of biological response modifiers, including the efficacy of chemotherapy. Here we used the automated laser scanning cytometry (LSC) for multi-parameter analysis of drug-induced tumor cell apoptosis. MATERIALS Using 2-mercaptopyridine-N-oxide-hydrate sodium salt, or the commonly used chemotherapeutic agents etoposide and camptothecin, we performed simultaneous analyses of apoptosis-related morphological features as well as fluorescence-based biochemical changes in a 96-well format. RESULTS We demonstrate the scope of LSC as a platform for comparing multiple variables between different cell populations, distinguishing unique events at a single cell level within a sample population, and enabling simultaneous screenings in a single assay at multiple dosages and time-points. CONCLUSION These data underscore the power of LSC for simultaneous multi-parameter analysis, which could have implications for screening or assessing the efficacy of drug responses in heterogeneous cell populations and at the single cell level.
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Affiliation(s)
- Andrea Lisa Holme
- ROS Biology and Apoptosis Group, National University Medical Institutes, Singapore
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